Interpretive Summary: Lygus hesperus is a major agricultural pest in the western United States, but many aspects of this insect’s feeding behavior are poorly understood. Saliva injected into the plant by Lygus bugs digests plant tissues and allows insects to feed. The saliva breaks down plant tissues long after feeding has ended, so it may be beneficial for Lygus bugs to return to previous feeding locations. Researchers at the USDA-ARS in Shafter, CA investigated whether Lygus bugs prefer to feed on cotton fruit that was preconditioned by earlier saliva injection compared with previously unvisited fruit. They found that Lygus bugs settle and feed on fruit that was preconditioned by earlier saliva injection more often than on fruit that was not preconditioned. Results from this study identified a previously unrecognized behavior of Lygus, which will help researchers better understand results from studies to develop crops that are resistant to Lygus bugs.

Technical Abstract:
Lygus hesperus is a major agricultural pest in the western United States. While feeding on plants, L. hesperus discharge lytic salivary enzymes that facilitate extraoral digestion of host tissues. These enzymes continue to digest plant tissues after cessation of feeding. Therefore it may be beneficial for L. hesperus to return to feeding locations that have been preconditioned by salivary enzymes discharged during earlier stylet-probing events. Video-behavior assays indicated the probability of L. hesperus adults visiting and feeding on a preconditioned squares was greater than the probability of the insect visiting control squares. These results indicate that L. hesperus adults prefer to feed on squares that have been preconditioned by prior stylet-probing events compared with squares that have not been previously stylet-probed. Results from this study demonstrate a previously unrecognized behavior of L. hesperus adults, and will improve interpretation of results in future studies of Lygus behavior and feeding injury on host plants.